1. Field of the Invention
The present invention relates to a control method and system for automated machines, and more particularly to a precision operational control method and system for an automated machine, wherein output data of an inertial sensor package installed in the grip or claw of the automated machine are received and processed in a central control processor for the automated machine , with electromechanical servo actuator valves and the surrounding loop controls to precisely control the movement of a motion element such as a grip or claw of the automated machine.
2. Description of Related Arts
Various automated machines, such as robots, smart cranes, etc., are being developed to facilitate automated operations, production, and processes. However, it""s still a challenge to design highly accurate operational controls for an automated machine.
The automated machine is configured with several major linkages, which produce the gross motion of the end effector. Without feeding back the motion sensed at the end effector, manipulation of its position and orientation has to be done at a slow speed and requires extensive operators""assistance.
It is a main objective of the present invention to provide a method and system for precision operational control of an automated machine, wherein a micro IMU(Inital Measuring Unit)(such as the U.S. patent application Ser. No. 09/477,151, filed Jan. 4, 2000, entitled xe2x80x9cmicro IMUxe2x80x9d, now allowed, and the U.S. Patent pending application Ser. No. 09/624,366, filed Jul. 25, 2000, entitled xe2x80x9ccoremicro(copyright) IMUxe2x80x9d) is incorporated, so that the acceleration, velocity, angle rate, and angle of the grip or claw of the automated machine are all commanded with high accuracy, and effects from the mechanical portions of the loop, such as the mechanical flexing and bending due to loading, and nonlinear torques due to hydraulic components are minimized.
Another objective of the present invention is to provide a method and system for precision operational control of an automated machine that enables autonomous/intelligent control of the automated machine""s end effector by incorporating an IMU to permit direct servo-control of the end effector""s acceleration, velocity, angular rate, and anglexe2x80x94this closed-loop system minimizes effects of such disturbances as mechanical flexing and bending due to loading and nonlinear torques due to hydraulic components.
Another objective of the present invention is to provide a method and system for precision operational control of an automated machine, wherein control loops are formed through the use of actuators and outputs of the IMU linked with software for enhanced performance and agile operation of the automated machine.
Another objective of the present invention is to provide a method and system for precision operational control of an automated machine, wherein the application aspects of the IMU is designed to enhance manual and automatic control of the machine. The use of the IMU was applied within the context of control loops that can enhance the machine""s motion profiles.
Another objective of the present invention is to provide a method and system for precision operational control of an automated machine, wherein the IMU is totally self sufficient to provide all data necessary for motion measurement of the machine.
Another objective of the present invent is to provide a method and system for precision operational control of an automated machine, wherein the control loops are configured starting with an inner loop and expanding the functionality With successive layers of outer loops.
In order to accomplish the above objectives, an IMU is installed at an end effector of a motion element of an automated machine, fast-response feedback control for both position and angle servo-loops (for the end effector) greatly decreases the operational time needed to complete a preplanned trajectory. In addition, the closed-loop control design provides stabilization and isolation of the end effector from external disturbances
The application of the IMU as a sensor for providing velocity and position of the tool with respect to the base of the automated machine expressed in the navigation (earth fixed) frame requires the use of specific processing methods and software in order to form the navigation solution.
This unique navigation solution is based upon the use of a set of equations performing an open loop computation with the inertial data as its input. This formulation of equations requires a periodic update of the open loop solution in order to bound the growth of system errors. The source of this update is the automated machine position measurement derived from the mechanical sensors in the system.
The performance enhancements gained by obtaining an inertially referenced solution to the position data is to increase the devices bandwidth, remove the effects of mechanical compliance and resonance, and to provide an earth fixed reference for the sensed motion of the automated machine.